Dyestuff intermediates of the benzoyl-benzoic acid series



' to give a dichlorbenzoyl-benzoic acid which Patented July 11, 1933 1 UNITED STATES RHYS JENKIN LOVELUCK a m aorta rier/ins, or eaai s aiiron'rn,"SCOTL ND, AssIeNons T0 SCOTTISH DYESYLIMITED, er GRANGEMOUTH, SCOTLAND DYETSTUFF INTERMEDIATES or aura smizoYL-imnzorohcrn SERIES No Drawing. Application filed September 9, 1930, Serial No. 480,815, and in Great Britain September 13,

This invention relates to the production of dyestuif intermediates and more especially to the production of benzoyl-benzoic acid.

It is already known that ortho-dichlorbenzene will condense with' phthalic anhydride in the presence of aluminium chloride probably has the constitution 3: 4L dichlor- Q-benzoyl-benzoic acid. T

Ne have now found that important dyestuff intermediates of the benZoyl-benzoic acid series may be obtained from this dichlor-benzoyl-benzoic acid by treating it with nit-rating agents followed, if desired,'by reduction. v

The primary product is nitrodichlor-benzoyl-benzoic acid. This, we find, is a very reactive body, probably because of the large number of negative substituents present.

e also find it can be reduced, for example with ferrous sulphate and ammonia to give amino-dichlor-benZoyl-benzoic acid.

The invention in brief consists in treating a dichlor-benzoyl-benzoic acid especial- 1 ly that which may be made by condensation ucts when-"made by those processes or by the obvious chemical equivalents thereof.

The following examples illustrate how the invention may be carried into efi'ect references to parts and to percentages being to parts and percentages by weight:-

EmampZe 1 '50 parts of the dichlor-ortho-benzoyl-benthe precipitate filtered olf, washed and dried! The weight of product obtained is about-52 ters Patent is parts and contains about 4.6% of nitrogen.

' This intro-product is dissolved in the least quantity'of 10% aqueous ammoniaand the solution heated to 80 C. 10%ammonia and powdered ferrous sulphate are then added alternately in small amounts, keeping the ammonia-in slight excess until the reduction is complete. The whole is then filtered hot, the precipitate of iron salts Washed thoroughly with hot water,-the filterate well cooled and acidified.

This is anotherexample of the nitration sulphuric acid monohydrate, A mixture of 11 parts of 98% nitric acid and 100 parts sulphuric acid monohydrate is slowly added and the Whole is then heated to"80 G. and maintained for three hours at this temperature, after which it is poured into water.

The precipitate is filteredofl, washed acid free and dried. It contains 4.51% nitrogen.

Example 3 This is an example of the reduction of the body prepared according to Example 2.

36 parts of nitr0-8, l-dichlor-ortho-benzoyl-benzoic. acidprepared according to the previous example are milled to a fine paste with 500 parts of water and the paste heated to C. 1 part of sodium chloride is added followed by 48 parts of iron pin dust which is sprinkled in over 12 hours. The mass'is stirred for 6 hours or until no nitro-compound remains. 7 parts of sodium carbonate is then stirred in and the Whole'filtered. "The amino S A -.dichlor'-'ortho -benzoyl -benzoic a acid is precipitated from the filtrate by acidifying with hydrochloric acid. This precipitate is filtered,-washedacid free and dried.

Havlngnow described our invention, What we claim as'new and desire to secureby Let- '31. A process for the preparation of benzoic acid derivatives which consists in mixing the dichlor-ortho-benzoyl-benzoic acid, obtainable by condensing ortho-dichlor-benr in) zene with phthalic anhydride, with about 5 times its weight of concentrated nitric acid kept at the ordinarytemperatures for about 1 hour, mixing the melt with a substantial quantity of water and removing. the precipitate.

2. Benzoic acid derivatives suchas maybe i I made by acting on dichlor-ortho-benzoyl-benzoic acid, obtained by condensing ortho-dichlor-be nzene with phthalic' anhydride, with concentrated nitric acid.

3. Benzoic acid derivatives such as may be made by treating the condensation product of ortho-dichlor-benzene with phthalic anhydride in the presence of aluminium chloride with anitrating agent.

4. Benzoic acid derivatives such as may be made by stirring'50 parts of the'dichl0r 0rthobenzoyl-benzoic acid, obtained by condensing ortho-dichlor-benzene with phthalic anhy-' dride, intoO parts of197% nitric acid kept at ordinary temperature for one hour, pouring the melt into water and removing the precipitate.

5. Nitro 3'3 dichloro-ortho-benzoyl-benzoic acid.

6. Amino-3,4-dichloro-0rtho-benzoyl-benzoic acid.

' 7. A nitro- 3',4 -dichloro ortho-benzoyL' zoic acid derivative, which comprises reacting with a nitrating. agent upon 3,4'-dichlor0- ortho-ben'zoyl-benzoic acid.

10. A processof producing a benzoyl-benzoic acid derivative, which comprises reducing the compoundobtained by following the processset forthin claim 9. r

In testimony whereof we have signed our names to this specification.

RHYS. JENKIN ,LOVELUCK; J OI-IN THOMAS;v i

ILLJ 

